Well capping device

ABSTRACT

A well capping device for shutting off flow through a conductor includes explosive means to cut the conductor and means for moving a valve plate across the conductor subsequent to explosively cutting the conductor.

United States Patent [19.]

Walker, Jr. et al.

I111 3,820,601 [451 June 28, 1974 WELL CAPPING DEVICE [75] Inventors:George E. Walker, Jr.; Dean P.

' Hemphill, both of Houston, Tex.

[73] Assignee: Shell Oil Company, Houston, Tex.

[22] Filed: Nov. 6, 1972 [21] Appl. No.: 303,889

[52] US. Cl. 166/55 [5]] Int. Cl. E2lb 29/00 [58] Field of Search166/55, 100; 251/1 [56] References Cited UNITED STATES PATENTSChristopher 166/55 X 3,716,068 2/1973 Addison l66/55 PrimaryExaminer-Geo. V. Larkin [5 7] ABSTRACT A well capping device forshutting off flow through a conductor includes explosive means to cutthe conductor and means for moving a valve plate across the conductorsubsequent to explosively cutting the conductor.

6 Claims, 4 Drawing Figures [1 WELL CAPPING, DEVICE BACKGROUND OF THEINVENTION l. Field of the Invention The present invention relates to adevice which may be utilized to cap a well when thesurface equipment hasbeen destroyed by fire, explosion or other means. The device is utilizedonly in an emergency. condition.

2. Description of the Prior Art Numerous approacheshave been proposed toshut off flow from a well over which control has been lost due toabnormal formation pressures, malfunction of equipment at the surface orthose caused by anunderground blowout, losing the mud column, causing anunderbalanced condition as related to the formation pressure.

One effective method of controlling a well which has blown-out is toinstall a shut-off valve at the surface. This can be done only when theconductor pipe at the platform level has not been destroyed. It would beaccomplished by utilizing a boom that can be controlled remotely from abarge adjacent the platform. Another method is the installation of stormvalves in the conductor string at .approximatelythe mud line. This typeof valve is usually held open by positive pressure applied from ,thesurface by way-of a control line and if the platform should be destroyedor the conductor string destroyed, pressure would be lost in the controlline and the valve would automatically close. Such apparatus are usuallyinstalled in a producing well and are not adapted for application to adrilling well.

Another technique )in use in offshore areas in instances where :thewell-head connection has been completely destroyed, is to drill a reliefwell adjacent the wild producing well and upon reachingtotal depth,heavy mud is pumpeddown the relief well and into the producing formationuntil communication is established with the well bore of the wild well.This is a costly and time consuming operation and is usually employedwhen pollution or potential pollution hazard is significant.

An even further method that has been proposed where the conductor stringhas not been destroyed is to pump a heavy fluid or some other weightingmaterial such as lead balls down the conductor string and hopefullykilling the well in this manner.

The present invention is intended to' be applied in an emergency typeoperation and is applicable to a producing well as well as a drillingwell. The device of the present invention is compatible with most ofthe'methods hereinbefore described and would supplement these methods inkilling a well over which control has been lost. 7 l

SUMMARY OF THE INVENTION device significantly reduces the probability ofplatform damage in the event that a well is lost and a fire or explosionresults.

These and other advantages are provided in the device of the presentinvention-which comprises a member-having a cylindrical bore throughwhich a conductor string passes. The member is provided with anelongated slot in which a movable plate ispositioned. the slot beingsubstantially perpendicular to the cylindrical bore in the member. Meansare provided in the device to move the plate within the slot and acrossthe cylindrical bore shutting off any flow through the cylindrical bore.The device is further provided with gripping means adapted to engage theconductor and anchor the device to the conductor string.

BRIEF DESCRIPTION OF THE DRAWING The nature and extent of the presentinvention will be more fully appreciated with reference to the drawingin which:

FIG. 1 shows-the device of the present invention installed around aconductor pipe at an offshore platfonn;

FIG. 2 is an enlarged view of the well capping device shown installed ona well conductor;

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2; and

FIG. 4 is a top view of FIG. 3.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. 2, there isshown well capping device ll surrounding a well conductor 10. The deviceis installed at the base of the conductor 10 as shown in FIG. 1 and nearthe sea floor 48. The device can also be installed toward the upper endof the conductor 10 or above the water surface 49 or it could bepositioned on the platform working deck. Clamp-up flanges 14 haveprovided, as by welding 15, on each of the mating halves 8 and 9. Theclamp-up flanges 14 have perforations therethrough for installing aplurality of bolts 16 or equivalent means to join the two halves 8 and9.

Referring to FIG. 3, the well capping device 11 has cylindrical bores20a and 20b through which the well conductor 10 passes. The diameter ofcylindrical bore 20a is slightly greater than 201; in order that theconductor 10 is not restrained after it has been explosively cut. Thelower cylindrical bore, 20!), has gripping means 21 for gripping thewell conductor 10 and anchoring the device 11 to the conductor 10. Thegripping means 21 can also be attached to the lower surface of thedevice 11 to engage the conductor 10. A slot 22 extends transverselyacross bore 20a and in which a valve plate 23 may move to seal the wellconductor 10 below the valve plate 23 thereby shutting off flow throughthe well conductor 10. The slot 22 may have a wedge shaped cross sectionto further aid in sealing and shutting off flow. The slot 22 has arecess 32 in its lower face, which may be concentric to the conductor 10but it may be any other suitable shape such as rectangular. A seal 32ais installed in the recess 32 with the seal 32a in sealingengagementwith the valve plate 23 when it is in a closed position or alternativelythe seal 32a can be installed in the bottom surface of plate 23. One ormore hydraulic cylinders 27 with a piston 25 and rod 24 can be used tomove the valve plate 23 along slot 22 and across well conductor 10. Eachhydraulic cylinder 27 has an end plate 28 with a boss 29 through whichhydraulic fluid may be introduced to the hydraulic cylinder 27. A shearpin 31 may be installed in the rod 24, if desired, to deliver an impactforce to drive the valve plate 23 through the conductor 10. The leadingedge of the valve plate 23 may also be triangular in crosssection tofurther aid in assuring a complete closure to flow through the conductor10. The cylindrical bore 20b has a recess 38 into which a conventionalexplosive charge 40 or a shaped explosive charge is inserted or placedprior to clamping the two halves 8 and 9 of the well capping devicetogether. Primacord or an electrical wire 33 may be connected to theshaped charge40 and run to a remote location such as a buoy situatedsome distance from the platform 50. A similar charge may also beinstalled in the hydraulic cylinder 27 with suitable connections out theboss 29 with primacord or electrical wire running to the same buoy asthe wire 33. In this way, the piston 25, provided with seal 26, may beused to drive the valve plate 23 across the well conductor 10.

To install a well capping device around the well conductor 10, the twohalves 8 and 9 would be assembled using the clamp up flanges 14. Oneside, if desired, could be hingably connected, but preferably, bothsides would be provided with clamp up flanges 14 so that the seal 32aand the explosively shaped charge 40 could be installed withoutdifflculty.

In operation, as would be the case with a well out-ofcontrol, the linearshaped charge would be set off cutting well conductor and the upwardflow of fluid (arrow A) would carry or lift the well conductor up andout of the cylindrical bore a. The valve plate 23 would then be drivento its closed position shutting off flow from the well. Well killingoperations could then be initiated without undue danger to personnelconducting the control operation.

We claim as our invention:

1. A device for shutting off fluid flow through a well conductor,comprising:

a housing member having a cylindrical bore therethrough for receivingsaid conductor, said member being divided into two mating halves alongthe longitudinal centerline of the cylindrical bore with each matinghalf having connector means for joining the two mating halves;

an elongated slot formed in said member and being substantiallyperpendicular to the longitudinal axis of said cylindrical bore;

a laterally movable valve plate positioned within said slot;

means for moving said valve plate within said slot;

means for moving said valve plate within said slot and across saidcylindrical bore;

a explosive-charge recess disposed in the wall of said cylindrical boreand positioned below said elongated slot; and

gripping means carried by said housing member to anchor said housingmember to said conductor.

2. The device of claim 1 wherein said slot is provided with a recess inits lower face and having a seal installed therein to sealingly engagesaid valve plate when said valve plate is in its closed position.

3. The device of claim 1 wherein said recess contains an explosive forcutting said conductor.

4. The device of claim 3 wherein said explosive is a shaped type ofexplosive.

5. The device of claim 1 wherein said means for moving said valve platecomprises at least one hydraulic piston and piston rod assemblyoperatively connected to said valve plate.

6. The device of claim 1 wherein the recess contains an explosive forcutting said conductor and the means for moving said valve plate withinsaid slot comprises two hydraulic pistons and piston rod assembliesoperatively connected to said valve plate.

1. A device for shutting off fluid flow through a well conductor, comprising: a housing member having a cylindrical bore therethrough for receiving said conductor, said member being divided into two mating halves along the longitudinal centerline of the cylindrical bore with each mating half having connector means for joining the two mating halves; an elongated slot formed in said member and being substantially perpendicular to the longitudinal axis of said cylindrical bore; a laterally movable valve plate positioned within said slot; means for moving said valve plate within said slot; means for moving said valve plate within said slot and across said cylindrical bore; a explosive-charge recess disposed in the wall of said cylindrical bore and positioned below said elongated slot; and gripping means carried by said housing member to anchor said housing member to said conductor.
 2. The device of claim 1 wherein said slot is provided with a recess in its lower face and having a seal installed therein to sealingly engage said valve plate when said valve plate is in its closed position.
 3. The device of claim 1 wherein said recess contains an explosive for cutting said conductor.
 4. The device of claim 3 wherein said explosive is a shaped type of explosive.
 5. The device of claim 1 wherein said means for moving said valve plate comprises at least one hydraulic piston and piston rod assembly operatively connected to said valve plate.
 6. The device of claim 1 wherein the recess contains an explosive for cutting said conductor and the means for moving said valve plate within said slot comprises two hydraulic pistons and piston rod assemblies operatively connected to said valve plate. 